1. Technical Field of the Invention
The present invention relates to novel cosmetic and/or dermatological compositions for the photoprotection of human skin and/or hair against the damaging effects of UV radiation, in particular solar radiation. More especially, this invention relates to novel cosmetic and/or dermatological compositions comprising at least one UV screening agent of dibenzoylmethane type and/or at least one UV screening agent of the type derived from benzylidenecamphor and/or at least one UV screening agent of the type derived from triazine, these compositions having an improved sun protection factor and which also comprise, in a cosmetically and/or dermatologically acceptable support (vehicle, diluent or carrier) therefor, at least one linear or branched dialkyl tartrate.
2. Description of the Prior Art
It is known to this art that light radiation having wavelengths of between 280 nm and 400 nm permits tanning of the human epidermis, and that light radiation having wavelengths of between 280 and 320 nm, known as UV-B irradiation, causes skin burns and erythema which may be harmful to the development of a natural tan; this UV-B radiation should therefore be screened from the skin.
It is also known to this art that UV-A radiation, having wavelengths of between 320 nm and 400 nm, which causes tanning of the skin, is likely to induce an adverse change therein, especially in the case of sensitive skin or of skin which is continually exposed to solar radiation. UV-A radiation causes, in particular, a loss of elasticity of the skin and the appearance of wrinkles, resulting in premature skin aging. UV-A radiation promotes triggering of the erythemal reaction or amplifies this reaction in certain individuals and may even be the cause of phototoxic or photoallergic reactions. It is thus desirable to also screen UV-A radiation.
Many cosmetic compositions suited for the photoprotection (UV-A and/or UV-B) of the skin are known to this art.
These antisun or sunscreen compositions are commonly in the form of an emulsion of oil-in-water type (namely, a cosmetically acceptable support comprising a continuous aqueous dispersing phase and a discontinuous oily dispersed phase) which contains, in various concentrations, one or more conventional lipophilic and/or hydrophilic organic screening agents which are capable of selectively absorbing harmful UV radiation, these screening agents (and their amounts) being selected as a function of the desired protection factor (the protection factor (PF) being expressed mathematically by the ratio of the irradiation time required to reach the erythema-forming threshold with the UV screening agent to the time required to reach the erythema-forming threshold without UV screening agent).